Control mechanism for internal combustion engines



June 25, 1940. HOFFMAN El AL 2,205,651 l I ACQNTJRO-L uucflmrs uyonmmauim coususnou mamas I g mied fob; 18.51937 j s shun- 5pm;

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June '25, 1940. s. K. HOFFMAN ET AL common uscmmxsu Fenv mwamucoueusuou Emma's F'iIed Feb. s, 19:57 s Sheets-Sheet- 2- N III" June 25, 1940. s. K. HOFFMAN El AL 2,205,651 common Iscwuusi FOR u -mu. coususnou suemss s Sheets-Sheet s Filed Feb. 8. 1937 N QN v zm m Patented. June 25, 1940 I 2,205,651

UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR. INTERNAL COMBUSTION ENGINES Samuel K. Hoffman and Leonard S. Wiener,

. Williamsport, Pa., assignors to Aviation Manu- I iacturing Corporation, Williamspott, Pa., a corporation of Delaware Application February a, 1937, Serial No. 124,112

Claims. (01.123-139) The invention relates to mechanism for confeatures which are hereinafter set forth and are trolling the supply of liquid fuel and air to inmore particularly defined by claims at the contemal combustion engines. clusion hereof.

One object of the invention is to provide im- In the drawings: Fig. 1 is a front elevation 5 proved air and fuel injector controls which are of control mechanism embodying the invention, 5 co-rclated or inter-connected, and by which the set in position for starting the engine. Fig. 2 full rich mixture strength provided will be of is a similar view illustrating the control mech-- the desired fuel-air ratio at the optimum engine anism set for a full rich mixture of fuel and speed on a normal load curve based on the reair. Fig. 3 is a similar view illustrating the conquirements of the engine, for example, when it trol mechanism set for producing a mixture of- 10 is used to drive an airplane propeller, as deterintermediate richness. Fig. 4 is a similar view mined by calibration of the particular design and illustrating the control mechanism set for comthe enrichment factors deemed advisable and by pletely cutting off the supply of fuel. Fig. 5 is which-the same fixed proportion of the full rich a view of parts of the mechanism for shifting mixture strength will be provided for all settings the throttle operating shaft. Fig. 6 is a section of the air-throttle or the control lever for a leaner on line 6-6 of Fig. 2. Fig. 7 is a section on line mixture or a reduced supply of air and fuel. 1-1 of Fig. 2. Fig. 8 is a sectional view of a Another object of the invention is to,provide portion of an engine with a fuel injector and an improved air and fuel injector controls which air throttle for which the control mechanism is are co-related or inter-connected so that the adapted. Fig. 9 is a diagram illustrating the mixture strength may be varied by a mixture fuel-air ratiospproduced with different throttle control lever adapted for different settings and and fuel injector settings. by which, for any throttle setting, the fuel in- The invention is exemplified in connection with jector will be set to correspondingly reduce the a shaft i5 which maybe connected by any suitsupply of fuel in direct proportion to any given able means to the air-throttle a: of an engine 1 25 engine speed and the fuel delivered will be a to change the throttle setting proportionately to proportionate percentage of the air delivered. the movement of said shaft and a shaft It for For example, if the mixturelever is set for 75% imparting movement to the variable control full rich mixture, then for any throttle angle or means for the fuel-injector mechanism 0 of i the setting, the fuel injector control will be-set for engine, to vary the volume of the charges of 30 a corresponding percentage of the full rich mixfuel injected or pumped to the cylinders of the I ture strength. The percen a e relationship over engine. For example, shaft l6-may be connected the entire range is desired for use as an altitude to the shaft (i of an arm 11- which is connected control. When once set at any altitude the corto angularly adjust an inclined pump-operating rect relationship will be held on propeller load disk 11 which is driven by the engine, as well 35 curve. understood'in the art, and is adapted to vary Another object of the invention is to provide the stroke of the fuel pumps d which meter the mp r and fuel injector controls which fuel, and control'the volume of fuel charges deare co-related 0r inter-Con e ed a by 9 livered to the engine. The constructionof fuel- 40 the fuel-Percentage for starting m be increased injector illustrated forms no part of the present 40 0 high that h use 9 a P not F invention and it is to be understood that the 1m- A still further ob ect of the invention 18 to proved controlling mechanism is applicable to provide improved air and fuel injector controls difierent types of fue1- injectors The connec which are inter'wnnected tions between the shaft l5 and the air throttle whereby the fuel supply may be and the shaft l6 and the fuel-injection control 4 to stop the engine irrespective of air supply.

are such as to produce variations in the settings Another ob ect of the invention 18 to provide of the air throttle and the fuel supply, which im oved air and fuel in'ector controls which are? co-related or inter-connected and by which are pmPortwmte to the movements of said Shafts the injector control will be automatically shifted respectlvely- 50 to supply the full rich mixture when the throttle, In h use of the invention w t en ines for I is closed to a predetermined point. propelling airplanes, the control. levers for the Other objects of the invention will appear from engine are generally placed in the -p 0 the detail description. the plane and shafts l5 and I6 are connected,

I The invention consists in the several novel 'by suitable means, to operate, respectively, the 55 air-throttle and the fuel-injector control of the engine.

The control-mechanism for co-relating the fuel injection and air throttle, comprises a hand- .lever I! which is centrally fulcrumed on a shaft II which is fixed in a suitable support l9; a link 29 having one of its ends pivoted at 2| to the lower end of lever an arm 22 pivoted to swing 29 which extends into a cam-slot 29 in cam 24' and adapted to shift the pin 29 to rock arm 21 and the shaft l5 for imparting movement to the air-throttle a. Shaft I5 is journaled in the fixed support l9 and a bracket l9. Cam 24 has an arcuate slot 24 to permit it to swing around shaft l5. Shaft 25 on which cam 24 fulcrums, is carried by bracket l9". Oscillation of lever I! by the operator will impart proportionate movement to the air-throttle operating shaft l5 through link 29, arm 22, link 23, cam 24, cam slot 29, and stud 29 on the arm 21 which is fixed to the throttle shaft. An index arm 3| is fixed to the shaft I5 and its distal end travels across an arcuate scale 30 to enable the operator to read or determine the settings of the air-throttle and the corresponding volume of air-admitted to the engine.

The control-mechanism comprises a linkage which is operable by the lever I1 and co-related to the air throttle control for variation of the fuel charges according to the proportions required for different throttle settings. The linkage for setting the fuel-injector control-shaft |6 in co-relation with the throttle setting by lever comprises an arm 32 on and rotating and swinging concentrically with the arm 22; an arm 33 fixed to arm 32 and provided with -a slot 34; a link 35 provided at one of its ends with a stud 36 extending into and adapted to travel in slot 34; and an arm 31 fixed to shaft l6 and operable by the other end of the link 35 to which it is pivoted at 38.

Slot 34 in cam 33 permits the stud 36 to be shifted to and from the axis of arms 22, 32 and shaft |5 to vary the proportional angular movement between the arm 31 and shaft l6 and the arm 33 and shaft |5' responsive to settings of lever H. The stud 36 is movable to and from the axis of arm 22 to increase or decrease the movement of arm 31 on the injector-control shaft 6 relatively to the movement of arms 33, 32, 22 and shaft l5 for the purpose of varying the fuelair ration of the mixture supplied to the engine.

The mixture control comprises a lever 39 which is centrally fulcrumed on stud l6 concentrically with the lever I1; a connecting rod 49' pivoted to the lower end of lever 39; an arm 4|- to which the other end of rod 49 is pivoted; a shaft 42 fixed to arm 4| and journaled in a bracket l9" which is fixedly secured to support I9; an arm 44 fixed to the front end bf shaft 42; and a link 45 pivoted at 46 to the distal end of arm 44 and to the stud 36which is slidable in the slot 34 and carried by connecting rod 35. Oscillation of lever 39 will, through connecting rod 49, arm 4|, shaft 42, arm 44 and link 45, move the stud '36 in the slot 34 to or from the axis of arms 33, 32 and shaft l5 to vary the stroke of link 35, arm 31 and the injector control shaft relatively to the lever I! and the throttle operating shaft l5. This constitutes a proportionality linkage variable by the mixture-control lever 39 to vary the proportionate movements of the shafts l6 and I6 and to correspondingly vary the settings of the throttle and the fuel-injector control. The injector control and the throttle control remain co-related' and are conjointly operable at all times by the lever l1 and by means of the mixture control lever 39 the proportion of the air admitted by the throttle and the fuel injected may be varied to vary the fuel-air ratio while both controls remain conlointly operative for different settings by the lever H.

The lower end of slot 34 in arm 33 is extended downwardlyto a point coincident with the axis of arms 33, 32 and shaft l5 to permit stud 36 tobe shifted into coaxial position with arms 33, 32 to render the proportionality linkage whereby shaft |6 will be shifted, ineffective or into its zero position so that the injector control will be set to completely cut off the supply of fuel to the engine while the air-throttle remains shiftableby lever II. This permits the lever 39 to be utilized to set the mixture control at zero for stopping the engine.

Ann 31 on shaft 6 carries an index arm 69 which swings across a fixed dial 6| to indicate in degrees, the settings of the fuel-injector control, to indicate the percentage of the full fuel charges which are being delivered to the engine.

Lever 39 swings across a plate 41 which is fixed to support l9 and is provided with a scale for indicating the settings of said lever. A setscrew 49 on a screw which is carried by lever 39 and extends through a slot 49 in plate 41, is adapted to lock the lever 39 in its assigned position.

A retraetible spring stop 59 extends through plate 41 and is adapted to be normally engaged by lever 39 to limit its movement in one direction. This stop is positioned to co-relate the settings of the air-throttle and the fuel-injector so that, as long as the air density remains constant, the fuel-air ratio shall be of the full rich mixture strength for all throttle angles. The term full rich mixture strength applies to the fuel-air ratio at rated power and speed and varying with throttle position according to the corresponding propeller or other load curve and engine requirements and the maximum enrichment for the optimum operation of the engine. The mixture strength may be varied by the shift of lever 39 throughout the full desired range from zero to full rich by adjusting lever 39 at positions of the throttle except in the compulsory enrichment range.

Stop 50 is on a resilient finger-lever, whereby the stop may be retracted from the path of lever 39 so it can be shifted beyond its full rich mixture position (Fig. 1) to set the fuel-injector control shaft l6 for the maximum fuel pump capacity while the throttle is open to, say, up to 10 so that the mixture will have a higher fuel ratio than full rich and will be sufficiently rich for starting the engine without priming.

There is also provided means for returning the mixture-control lever 39 to its full rich settingwhen the throttle is nearly closed at lean mixture settings. This means comprises a rod 5| pivoted to the arm 22 which is shiftable by lever through link 29; a stud 53 through which rod 5| is slidable; an arm 54 in which stud 53 is journalled and which is rigid with shaft 42 and arms 4| and 44; and an adjustable stopnut 55 threaded to the free end of rod 5|. A

lock-nut 55 secures the nut 55 in its assigned 5 stop-nut 55 will abut 2,205,051 position. When the mixture control lever-.33 is set for a lean mixture and lever 'll'lis set 'to close the throttle beyond a predetermined degree, say 26, arm 22 will hold rod 5| so that against stud 53 during the further movement of lever I! to reduce the throttle angle below 26, which will cause nut 55 to shift stud 53 and rock arms 54, l4 and ll.- Arm AI will thereupon shift rod 33 to bring lever '33 against the full rich stop 50. Simultaneously the injector-control shaft It will be shifted to its full rich mixture setting through the movement of shaft 43, arm 44, link 45, stud 36, link 35 and arm 31. As a result, whenever the throttle is set for less than a predetermined angle, while the mixture control lever is set for too lean a mixture for operating the engine, at lower throttle settings, the fuel-injector control willbe set, concurrently with the setting of lever H, for a full rich mixture, as shown in Fig. 2. By adjusting the nut 55 on rod 5|, .the zone of compulsory enrichment may be varied for the minimum throttle opening desired. The chart (Fig. '7) indicates the settings of the full injector-control and the air-throttle openings in degrees in different positions of the levers l1 and 39. The of the fuel-injection and the degree of throttleopening angle during the full range of the settings of the lever l'l while the mixture control lever,39 is in its full rich mixture position (Fig. 2) or against the stop 50. The line b indicates the percentage of fuel-injection during the full range of settings of lever ll when the mixture control lever 33 is set for a 75% full rich mixture. The line 0 indicates the percentage of fuel supply during the full range of the settings of lever I! while the mixture control lever 39 is set for a 50% full rich mixture. The line d indicates the percentage of fuel injection to the engine during the full range of settings of lever l-I while the mixture control lever' 33 is set for 25% of the full rich mixture. The zone e indicates the compulsory enrichment area, which mixture position while the reduced to less than 26. the percentage of fuel dewhile the mixture lever 39 the fuel-injector capacity will vary with the air flow through the throttle. as indicated bv the curve a, to maintain the maximum desired fuelair ratio for engine speed on a normal propeller or load curve.

For operating with a reduced mixture strength, the mixture control lever 33 may be set anywhere between its zero position and the stop 50. For example, if it is set at the point for a 75% full rich mixture. the fuel-air ration will be as indicated by line 25%, the fuel-air. ratios ,will be as shown by 0 lines o and d. The fuel-injector will be set for corresponding percentages of the full rich mixture. The fuel-supply is directly proportional to the position of the mixture control lever 33 for any given engine speed and, as a result, the 5 fuel delivered at any throttle setting will be a livered to the engine line a indicates the percentage control shaft I 6 results from shifting of the mixture control lever claims, without departing scope of the invention.

53 and above its full .bustion engines, the

b, or if set at 50 or corresponding percentage of the amount'deliveredat the same air setting.

When lever- 39 is shifted for varying the fuelair ratio, the stud 36 will be shifted to and from the axis of arm 32 and resultantly the proportional movement of the injector-control shaft l6 will be increased or decreased relatively to the shift of the throttle control shaft l5 and the throttle.- Consequently, the fuel deat any throttle setting will be of a percentage of the air flow at the different throttle settings. For starting the engine when it is ,cold the lever 33 is advanced beyond the retractible stop 50 to shift the stud 36 to the outer end of slot 34 in'arm 33 (Fig. 7) and the lever l'l will'be shifted to a point having its starting range, say 10, open. Lever I! will then control the throttle up to a 10 angle, as indicated by the zone f, so that the mixture will be of sufllcient richness flow with full richmixture.

to effect a speedy starting of the engine. With this setting it is possible to obtain the maximum capacity of the fuel-injector with the throttle nearly closed. The maximum available injector setting is available at any throttle angle.

' The engine can be stopped by advancing the throttle lever to a point more than 26 open and setting the mixture control lever 33 at zero percentage of the rich mixture strength (Fig. 4). In this position of lever or on the dead center of arm 33, so that it will be inoperative to shift link 35 and the injector until lever ll is shifted. When stud 36 is on the dead-center of arm 32, shaft It; will be positioned to cut of! the delivery of fuel by the injector mechanism.

At any setting of mixture control lever 33 for less than its full rich mixture, the lever l1, when it is shifted to close the throttle to below 26 will automatically shift the proportionality linkage (arm 33, stud 33, link 35 and shaft l6) for the full rich mixture.

The invention is not to be understood -asrestricted to the details set forth, since these may be modified within the scope of the appended from the spirit and Having thus described the invention, what we claim as new and desire to secure by letters Patent is:

1. In controlling mechanism'for internal comcombination with a variable force-feed fuel injector and an air throttle of controlling means for the injector and the throttle comprising a control-lever, connections operable by the lever for simultaneously shifting the throttle and varying the fuel injector to vary,

the supply of both air and fuel at a constantly maintained ratio through substantially the entire range of variation, said connections comprising an adjustably connected arm and link,

andmeans for adjusting the connection between the arm and link to vary the fuel-air ratio and into position to bring one end of the link to the axis of the arm to render the arm ineffective to shift the link.

2. In controlling mechanism for internal combustion engines, the combination with a variable force-feed fuel injector and an air throttle of "controlling means for the injector and the throttle comprising a control-lever, connections operable by the lever for simultaneously shifting the throttle and varying the fuel injector to vary the supply of both air and fuel at a constantly 39, stud 36 is coaxial with tire range of variation, justing the connections to vary the fuel-air ratio, and meanslfor automatically adjusting the connection to increase the fuel percentages, when the control-lever is shifted low a predetermined point.

3. In controlling mechanism for internal com-v bustion engines, the combination with a variable force-feed fuel injector and' an air throttle of controlling means for the injector and the throttle comprising a control-lever, connections operable by the lever for simultaneously shifting thethrottle and varying the fuel injector to vary the supply of both air and. fuel at a constantly maintained ratio through substantially the entirerange of variation, a lever for relatively adjusting the connections to vary the fuel-air t ratio, and a retractible stop positioned to stop the adjusting lever at a full rich mixture setting and releasable to permit the control-lever to be shifted for a higher fuel-percentage for starting.

4. In controlling machanism'for internal combustion engines, the combination with a variable force-feed fuel injector and an air-throttle, of

controlling means for the injector and the throttle comprising a control-lever, connections operable by the lever for simultaneously shifting the throttle and varying the.fuel injector to vary 30' the supply of both air and fuel at a constantly maintained ratio throughout substantially the to reducethe air beg 2,206,051 maintained'ratio, through substantially the en-{ a lever for relatively.ad-

entire range of variation, said connections comprising an arm to which the control lever is connected, a cam rotatable by said arm, a link having pivotal and sliding connection with said cam and connected to shift the throttle, an adjusting lever pivoted concentrically with the control-lever, and a connection between the adjusting lever and the throttle shifting link for adjusting the connectionbetween the link and the cam.

5. In controlling mechanism for internal combustion engines, the combination with a variable force-feed fuel injector and an air throttle, of controlling means for the injector and the throttle comprising a control-lever, connections operable by the lever for simultaneously shifting the throttle and varying the fuel injector to vary the supply of both air and fuel at a constantly maintained ratio throughout substantially the entire range of variation, said connections comprising an arm to which the control lever is connected, a cam concentric with and operable by said arm, a link having pivotal and sliding connection with said cam and connected to shift the throttle, an adjusting lever, and a connection between the adjusting lever and the throttle shitting link for adjusting the connection between the link and the cam.

SAMUEL K. HOFFMAN. LEONARD S. WIENER. 

